Smoke-preventer furnace.



No. 740,743. PATENTED OUT. 6, 1903.

' R. W. GAVENAUGH.

SMOKE PREVENTER FURNACE.

APPLICATION FILED APR. '1, 1900. RENEWED MAR. 'z, 1903.

N0 MODEL. v a SHEETS-SHEET 1 Hlllllllll Wznmsss: INVENTOR 5M 57 42% No. 740,743. PATENTBD 001?. 6, 1903. R. w. OAVENAUGH. SMOKE PREVENTER FURNACE.

APPLIOAIION FILED APR. 7. 1900. RENEWED MAB. I, 1903. 1 N0 MODEL. 3 SHEETS-SHEET 8.

I 0000 ,OQOQ QIQ OOOOOOO'POD inc. 740,743.

UNITED STATES i'atented Cctober 6, 1903.

PATENT OEEIcE.

SMOKE-PREVENTER FURNACE.

SPECIFICATION forming part of Letters Patent No. 740,743, dated October 6, 1903. Application filed April 7, 1900. Renewed March 17, 1903. Serial No. 146,756. (lilo model.)

To all whom it may concern: i

Be it known that I, RALPH Wnoonrr CAV ENAUGH, a citizen of the United'States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Smoke- Preventer Furnaces; andI do declare the following to be a full, clear, and exact descrip-.

tion of the invention, such aswill enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanyingdrawings, and to the figures of reference marked thereon, which the automatic supply of heated air to the fuel' of the fire-box along with steam injected into the box, the construction being such that as the steam is automatically injected into the fire-box heated air is at the same time automatically drawn from beneath the fire-box and injected over the body of the fuel in the fire-box, such'supply of steam and air being automatically out 01f, so that after the fresh fuel has been cokcd the supply of heated air will be cut off from above the fuel and will.

be caused to pass up through the grate-bars and through the body of the fuel from beneath the fire-grate.

The purposes of the invention are to supply at the proper time the requisite amount of steam and heated air to the fresh fuel and after the fuel has been coked to out off the supply of steam and air from above the fuel and to direct the air up through the body of the fuel from beneath the fire-grate and also to prolong the life of the fire-box;

To the accomplishment of the foregoing and such other objects as may hereinafter appear the invention consists in the construction and also in the combination of parts hereinafter particularly described and then sought to be clearly defined by the claims,

reference being had to the accompanying drawings, forming a part hereof, and in which- Figure 1 is a front elevation of a boilerfurnace with my invention applied thereto. Fig. 2 is afront elevation with the front plate of the furnace removed and illustrating the fire-box in section. Fig. 3 is a longitudinal sectional elevation through the furnace. Fig. 4 is a detail section, on an enlarged scale, through one side of the fire-box and steam and air injector. Fig. 5 is a' detailfside elevationof one side of the fire-boig'and Fig. 6 is a vertical section through the same.

In the drawings, the numeral -1 designates the masonary'part of the furnace; *2, the front or face plate; 3, the doors in front of the tubular boiler; 4, the door to feed the fuel to the fire-box, and 5 the door to the ash-pit.

The numeral 6 designates a steam-pipe leading from the steam-dome of the furnace or other source of steam-supply and delivering steam through the pipe"? and its branches 8 to the steam-pipes 9, extending along the opposite sides of the fire-box, so as to inject,

steam over the bedof fuel. The supply-pipe 6 is provided at the point 10 with a; valve, which is connected by rod 11 with the piston in a water-cylinder 12, to which water is supplied from a city main or other source through the pipe 13, which at the point 14: is provided with a valve actuated through a rod 15, which has a flap 16 in the line of movement of the door 4, so that when the door is opened the valve will be opened to admit water through the pipe 13 into the cylinder 12, beneath the piston therein, said pipe 13 also being provided with a valve 15, which will control the overflow of water from the cylinder 12, and thus regulate the gradual cutting off of the steam by the valve at 10 as the piston-rod descends, the escape of water fromthc pipe 13 being received by the pipe .16, which leads to a sewer or other point of discharge.

The numeral 17 designates a lubricator, and 18 a steam-trap connected: by the pipe '19 to the steam-supply pipe 6.

The several parts so far described may in details of construction be in accordance with Letters Patent granted to me by the United States November 16, 1897, No. 593;516'5,'or of any other approved type of construction.

Under the present invention I form the opposite sides or walls of the fire-box of metal, so as to form hollow walls, eachwall being formed of metallic plates,which may he stayed by any number of stay-bolts 21, said walls at opposite ends being formed with the heads 22, which extend beyond the walls of the chamber, so that the projecting parts may fit into the brickwork of the furnace and also bear against the front of the furnace, as illustrated in Fig. 3, the front heads of these chambers being formed with openings covered by the caps 23, so as to permit access with the interior of the hollow walls forthe purpose of cleaning out the same. Each wall has extending transversely through its upper portion any desired number of tubes or thimbles 24, whose ends may be upset against the outer faces of the walls, which tubes or thimbles not only serve to stay the walls, but also to receive the steam and air mixing tubes 25. These mixing-tubes open into the fire-box on its opposite sides and at their outer ends receive the steamnipples 26, leading from the steam-pipes 9, and by which steam is injected through the mixing-tubes into the fire-box. The rear ends of the mixing-tubes are open, and they communicate with the flues or air-channels 27 which lead from the ash-pit below the fire-grate, so that as steam is injected into the mixing-tubes air is sucked from beneath the fire-grate and into the mixing-tubes, where the steam and air combine and are impelled by the steam-jets through the mixing-tubes into the fire-box. The mixing-tubes 25 are conical in form and the space between them and the tubes or thimbles 24 is filled or packed with asbestos 28, which protects the parts against intense heat and serves to insure close joints between the parts. This packing also serves to prevent the mixing-tubes from working their way out at the rear of the fire-box, and the tubes are also formed with bent or overhanging ends 29, which extend over the steam-pipes 9, which overhanging parts will prevent the mixing-tubes from working inwardly toward the fire-box.

Each of the hollow walls 20 connects through a pipe 30 with the tubular boiler below the water-line, so that the hollow walls will be supplied with water from the boiler, and from each hollow wall extends another pipe 31, which will also lead to the boiler. Each hollow wall will also be provided with one or more blow-off pipes 32, which may be made to lead to the outside of the masonry of the furnace.

The numeral 33 designates the fire-grate, which at the bridge-wall end rests upon aledge 34 and at the opposite end upon a ledge 35.

The air flues or channels 27 where they open into the fire-pit below the grate are provided with dampers or valves 36,mounted upon rods 37, journaled in suitable bearings and extending through the front of the furnace, where they are provided with cranks 38, connected together bya rod 39, and from said rod or one of the cranks a chain or wire rope passes around a sheave 41 and is connected with the piston of the water-cylinder 12 through the instrumentality of a rod 42, extending from the piston through the lower end of the cylinder, which rod may have weights 43 suspended from its lower end, the Wire rope or chain 40 being illustrated in the drawings as connected at the lower end of the weights, thus connecting the chain with the rod, which extends from the piston and through the lower end of the cylinder 12. It will be observed that by this arrangement when the piston is raised by the actuating agent admitted to the cylinder, so as to open the steam-valve for admitting steam above the fuel in the firebox, at the same time the rope or chain 40 is pulled so as to open the dampers or valves 36, thus admitting warm air to the flues or channels 27, which air is sucked by the steam-jets and impelled along with the steam through the mixing-tubes 25 into the fire-box above the fuel, and, further, that as the steam is gradually shut off by the piston and the cylinder 12 moving downward the dampers or valves 36 are gradually closed. By this arrangement steam and warm air are admitted to the firebox after each fresh charge of fuel is supplied and until the fuel is coked and that after that takes place both the steam and air are shut oif from above the fuel, the valves or dampers 36 when closed preventing the air from being sucked from the fire-pit and up through the flues or channels 27 and hence when the air is shut off from those channels it must pass up through the body of the fuel from the firepit. This produces the best results and the most intense heat and effectually prevents the formation of smoke. A

I have illustrated and described the construction and arrangement of parts well adapted to effect the operation described, but changes can be made in the details of construction and arrangement so as to obtain the same result and without departing from the scope of this part of my invention.

By constructing the fire-box with hollow walls formed as described the life of the firebox is materially prolonged and the efficiency and durability of a smoke-preventer furnace materially increased.

Having described my invention and set forth its merits, what I claim is 1. In a smoke-preventer furnace, the combination of the fire-box having hollow walls set into the brickwork of the furnace and having tubes extending through the same which are open at both ends, pipes connecting the interior of said walls with the waterspace of the boiler, air channels or flues leading from the fire-pit and in communication,

with the fire-box through said tubes, and steam-injecting nozzles opening'into said tubes at the junction of the same with the upper ends of the air-channels, substantially as described.

2. In a smoke-preventer furnace, the combination with the fire-box having hollow walls in communication with the water-space of the boiler,.said hollow walls having tubes extending transversely to the same, a steam and air mixing tube in each of the tubes of the hollow walls, said mixingtubes being open at opposite ends, a steam supply pipe having steam-jets opening into said mixing-tubes, and air channels or iiues leading from the fire-pit and communicating with the mixingtubes at the end where the steam is injected into the same, substantially as described.

3. In a smoke-preventer furnace,the combination of the fire-box having hollow walls provided with pipes communicating with the boiler and having blow-off pipes, said-hollow walls having tubes extending transversely through the same, steam an (1 air mixing tubes lying within said transverse tubes of the hollow walls, steam-supply pipes having steamjets opening into the mixing-tubes, and air fines or channels leading from the ashpit and communicating with the mixing-tubes, substantially as described.

4:. In a smoke-preventer furnace,the combination of the fire-box having hollow walls provided with pipes communicating with the boiler, said hollow walls having tubes extending transversely through the same, steam and air mixing tubes lying within said transverse tubes of the hollow walls, said mixing-tubes having depending overhanging parts at their rear, a packing between said mixing tubes and the transverse of the hollow Walls, steamsupply pipes beneath the overhanging parts of the mixing-tubes and having steamjets opening into said tubes, and air lines or channels leading from the ash-pit and communieating with the mixing-tubes, substantially as described. e 3

5. In a smoke-preventer furnace, the comb'i-' nation with the fire-box and ash-pit, of an airtime in the wall of the fire-box and in communication at its upper end with the fire-box and at its lower end with the ash-pit and closed to communication with said parts at otherpoints whereby at certain periods there may be an uninterrupted passage of warm air from the ash pit through said fine to the upper part of the fire-box unaifected by the opening of the f urnace-door, a valve-controlled steam-supply pipe entering the upper end of said flue for creating a suction in said flue from the ashpit and impelling warm air drawn from the ash-pit together with steam over the fuel in the fire-box, a damper to the air-flue, a pressurecylinder having a connection with said damper and with the valve of the steanrsupply pipe and provided with an inlet-valve operatively connected with the furnace-door and having an escape for the pressure agent, whereby as the furnace door is opened the pressure agent is admitted to the pressurecylinder andthe steam-supply-pipe valve and damper to the air-flue are opened to supply steam and warm air to the fuel, and as the door is closed,the supply of the pressure agent is cut oif and the agent inthe cylinder escapes therefrom and the steam-supply valve and damper to the air-flue gradually closed, sub--.

stantially as described.

6. In asmoke-preventerfurnace,the combination with the fire-box and ash-pit, of airflues formed in two walls of the fire-box and in communication attheir upper ends with the fire-box and at their lower ends with the ash-pit, a valve-controlled steam-supply pipe having parts thereof entering the upper ends of said air-fines, dampers to said air-fines, a pressure-cylinder provided with a piston having one part of its rod extending through one head of the cylinder and connected with the steam-supply-pipe valve and another part extended through the other head of said cylinder and connected with the dampers tothe airfiues, an escape-pipe leading from the pressure-cylinder, and an inlet-pipe for the pressure agent having a valve operatively connected with the furnace-door, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

RALPH WAGGETT CAVENAUGH. Witnesses:

CHARLTON W. CRANE, Rom. PARKHUBST. 

